The present invention relates to a filter device for separating unwanted particulate material from molten or flowable plastic material, such as thermoplastic polymer, wherein a stream of plastic material having particles, such as dirt, lumps and/or carbonised polymer entrained therein, is fed to the inlet side of the filter device, for processing.
More precisely the invention relates to an automatic screen changer particularly suitable for production of pellets in recycling of plastics, in which use is made of a filter element comprising a filter band or wire net which is step advanced or moved throughout a filter chamber, across a flow path for the plastic material to be processed and cleaned from the unwanted particles.